@article {4188, title = {The geochemistry of glacial deposits in Taylor Valley, Antarctica: Comparison to upper continental crustal abundances}, journal = {Applied Geochemistry}, year = {2019}, month = {05/2019}, abstract = {

Wet-based glacial deposits have been used traditionally as an analog for upper continental crust (UCC) abundances. To provide more information on the validity of using glacial deposits from wet-based glaciers, samples deposited by the dry-based polar glaciers located in Taylor Valley, Antarctica, were collected. Stream channel sediments, comprised of igneous, metamorphic, and sedimentary rocks initially deposited as glacial tills by polar glaciers, were analyzed by XRF, ICP-MS, and SEM. Based on the Chemical Index of Alteration values and A\–CN\–K ternary diagram, there are low levels of chemical weathering in these tills. Additionally, major and trace element geochemical data are compared to the average UCC values. The observed discrepancies between the mean UCC and Antarctic samples develop from the existence of mafic components, most likely the McMurdo Volcanic Group and Ferrar Dolerite, being present in the Taylor Valley tills. Even though the mafic material typically comprises 3\–7\% of the till, the volcanic rocks have a significant influence on the tills\’ bulk geochemistry. The existence of this mafic fraction in the dry-based glacial tills results from the reduced rate of weathering, as compared to wet-based glaciers. Geochemical analyses of the dry-based glacial tills in polar deserts, such as those found in Taylor Valley, may provide a better representative composition of the original material than wet-based glaciers and need to be incorporated into upper continental crust calculations.

}, keywords = {LTER-MCM, Antarctica, geochemistry, glacial deposits, polar dry-based glaciers, Taylor Valley}, doi = {10.1016/j.apgeochem.2019.05.006}, url = {https://www.sciencedirect.com/science/article/pii/S0883292719301246}, author = {Carolyn Dowling and Sue Welch and W. Berry Lyons} } @article {3216, title = {The effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons}, journal = {Antarctic Science}, volume = {26}, year = {2014}, month = {Jan-08-2014}, pages = {331 - 340}, abstract = {

Small changes in the availability of liquid water can have profound effects on the water levels, aqueous chemistry and biogeochemical dynamics of the closed-basin, perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica. We have compiled the published and unpublished data on dissolved gas, tritium and chlorofluorocarbons (CFCs) for Lake Fryxell and Lake Hoare to determine the effects of a high meltwater year (2001\–02 summer) on the lakes. The dissolved gas, tritium and CFC data indicate that the pulse of freshwater that flowed onto the surfaces of the lakes did not mix extensively with the upper water column. At the bottom of Lake Hoare, the measurable CFC and lower dissolved gas values suggest that the recent meltwater may have mixed with bottom waters. The probable mechanism for this transportation is weak density currents with\ c. 0.1\–1.5\% surface water being transported downwards in Lake Hoare. This deep water input, while not constant, may have a significant effect on the chemistry of the bottom waters in Lake Hoare over time. In Lake Fryxell, the tritium and CFC data indicate that the recent meltwater did not significantly affect the bottom water chemistry; therefore, weak density currents may not be present in Lake Fryxell.

}, keywords = {LTER-MCM}, issn = {0954-1020}, doi = {10.1017/S095410201300062X}, url = {http://www.journals.cambridge.org/abstract_S095410201300062X}, author = {Carolyn Dowling and Robert J. Poreda and W. Berry Lyons} } @article {1258, title = {A stable isotopic investigation of a polar desert hydrologic system, McMurdo Dry Valleys, Antarctica}, journal = {Arctic, Antarctic, and Alpine Research}, volume = {38}, year = {2006}, month = {02/2006}, pages = {60-71}, keywords = {LTER-MCM}, doi = {10.1657/1523-0430(2006)038[0060:ASIIOA]2.0.CO;2}, author = {Michael N. Gooseff and W. Berry Lyons and Diane M. McKnight and Bruce H. Vaughn and Andrew G Fountain and Carolyn Dowling} } @article {1294, title = {Dating water and solute additions to ice-covered Antarctic lakes}, journal = {Geochimica et Cosmochimica Acta}, volume = {69}, year = {2005}, pages = {A720}, keywords = {LTER-MCM}, author = {W. Berry Lyons and Carolyn Dowling and Kathleen A. Welch and Snyder, G and Robert J. Poreda and Peter T. Doran and Andrew G Fountain} }